Kelly et al. in British Pat. No. 1,550,614 disclose an absorbent material suitable for incorporation in sanitary towels, tampons and napkins comprising an absorbent starch derivative, preferably a cross-linked starch, distributed in a flexible resilient polyurethane foam.
W. R. Grace & Co. in British Pat. No. 1,538,809 disclose a hydrophilic polyurethane foam in which a cross-linked carboxymethylcellulose and other water soluble or water dispersible materials such as sodium carboxymethylcellulose are incorporated.
Chen in U.S. Pat. No. 3,972,328, Steer et al. in U.S. Pat. No. 4,341,207, and Pawelchak et al. in U.S. Pat. No. 4,538,603 and European Patent Application No. 92,999 disclose multi-layered dressings including an intermediate layer of semi-open cell polyurethane foam and an adhesive layer which contacts the wound and surrounding skin. Lindquist et al. in U.S. Pat. No. 3,665,918 disclose a surgical tape or drape consisting of compressed polyurethane foam coated with a microporous pressure sensitive adhesive.
Richter et al. in U.S. Pat. No. 3,566,871 disclose a hydrophilic polyurethane sponge for medical use in which the sponge pores contain a surfactant coating. McRae et al. in U.S. Pat. No. 3,978,855 disclose a polyurethane foam surgical dressing in which a surface of the foam is compressed and wherein the foam also contains a wetting agent. Lock in U.S. Pat. No. 3,975,567 discloses a polyurethane foam surgical dressing in which one surface is rendered lyophilic by applying pressure and heat. Lazlo in European Patent Application No. 41,934 disclose a wound exudate absorbent product comprising a polyurethane foam having a water-insoluble hydrophilic polymer such as cross-linked dextran incorporated within a portion of the foam cells. Marsan in U.S. Pat. No. 3,713,445 discloses an ostomy sealing ring consisting of an open cell polyurethane or polyethylene foam containing a gelatinous material such as karaya powder and glycerine. Various polyurethane foam dressings are disclosed by Robins in U.S. Pat. No. 3,113,568, Bentov in U.S. Pat. No. 3,157,178, Wheeler in U.S. Pat. No. 3,648,692, and Nowakowski in U.S. Pat. No. 3,949,742.